One of the most important phases of dairy production is that of feeding and managing dairy calves. Current mortality statistics reveal approximately 20-25% of dairy calves die before reaching maturity. These deaths may be caused by improper nutrition, or more frequently, by infections due to pathogenic microbial species. However, by supplying the calves with the proper mutualistic microbes, limited spectrum antimicrobial compounds which act against pathogens, as well as the proper supplements and nutritional additives, these losses may be greatly reduced.
Physiologically, the newborn calf is not a functioning ruminant. The calf is a true functional ruminant approximately twelve weeks after birth. The preruminant stage is a difficult time in the health of the calf because neither the rumen nor the intestinal tract have been fully and effectively colonized by the mutualistic microorganisms required by the calf to maintain proper health.
The rumen of bovine species is colonized by microorganisms which serve several purposes. The mutualistic microbes within the rumen allow the animal to breakdown feedstuffs into their component parts, which are used to synthesize microbial protein, which provides the ruminant with a portion of its protein requirement. The microbes within the rumen also synthesize and supply many of the nutrients, including most of the water soluble vitamins, required by the animal. Since preruminant calves are not true functional ruminants, these calves require a high quality, well balanced liquid feed containing all of the nutrients necessary to maximize growth and maintain health.
Additionally, the intestinal tract of the newborn calf is sterile. The sterile intestinal tract is then colonized by successive waves of microorganisms. Some of the microorganisms which colonize the intestinal tract during the early waves of colonization may be detrimental to the health of the calf. It is therefore important to take steps to inhibit the growth of any pathogenic microorganisms within the preruminant calf's intestinal tract, as well as stimulate the growth of beneficial bacteria therein.
Colostrum is a main source of feed for preruminant calves, particularly the first few days after birth. Colostrum is the milk which is high in immunoglobulins, and which is secreted by cows, and other mammalian females, for the first few days following parturition, and is a main nutritional source for neonatal calves.
Colostrum is used as a preruminant calf feed for a number of reasons. First, because bovine species do not undergo placental transfer of immunoglobulins, neonatal calves have no antibodies to provide them natural protection against disease. The immunoglobulins present within the colostrum provide a level of passive immunity for the calves. Second, the calves' immunity immediately following birth is virtually nonexistent and their intestinal surfaces basically sterile, thereby providing a high likelihood that the calves may become infected with highly pathogenic bacteria immediately after birth. Colostrum is used to provide protection against colonization of the calf by pathogenic organisms.
Colostrum is one type of liquid feed known in the art used in an attempt to supply the proper nutrition and immunoprotection to preruminant calves. However, the use of colostrum as a primary feed for preruminant calves has several problems associated with it. First, the quality of the colostrum, which is based on amount of immunoglobulins contained therein, varies between individual cows and also declines over time. The level of immune protection afforded a calf from the first milking colostrum obtained from the cow immediately postpartum is much greater than the level of immune protection supplied by colostrum obtained from subsequent milkings. Further, the levels of vitamins, minerals and other nutrients required by the calf found in the colostrum vary from milking to milking and cow to cow. Additionally, a cow may be "dry", e.g. not give milk, or may die immediately following birth of the calf, resulting in insufficient colostrum availability.
Another source of nutrition known in the art for a preruminant calf is milk that cannot be sold but is used as calf feed. Such milk is usually obtained from initial milkings following antibiotic treatment of a dairy cow for a number of syndromes, including uterine infections and mastitis, and is known as hospital milk, sick cow milk or pot milk (collectively referred to as "hospital milk"). Because this milk is unsalable, hospital milk is fed to calves rather than disposing of it. However, this milk varies in nutritional quality, is not a significant source of immunoglobulins, and additionally can be the source of pathogenic bacteria, especially if from mastitic cows. Further, hospital milk may contain antibiotic residues within the milk.
"Unsalable milk" is defined as milk which can not, by law, be sold for human consumption. Unsalable milk includes both hospital milk and colostrum. Dairy producers frequently mix all unsalable milk together, including colostrum, to be used as calf feed, which dilutes any health benefits supplied by the colostrum to the preruminant calves.
Finally, whole milk or milk replacer are widely used as liquid feeds for preruminant calves.
However, feeding whole milk to calves is usually cost prohibitive. Whole milk may lack sufficient amounts of vitamins and minerals needed by preruminant calves being raised in stressful situations, which may include poor management and sickness. Further, whole milk does not contain significant levels of immunoglobulins to aid in protection against pathogens.
Non-medicated milk replacers (hereinafter "milk replacers") are formulated feeds designed to replace the dam's milk for calves during critical, early suckling or milk feeding stages of life. Milk replacers generally contain 20-24% protein, preferably derived from milk products (e.g., whey, whey protein concentrate or skim milk); 10-20% fat, preferably derived from animal fats although other fat sources may be used; carbohydrates, mainly from lactose; and essential vitamins and minerals. Milk replacers are reconstituted with water, mixed and fed according to the directions of the manufacturer. For dairy producers, it is generally more profitable to sell the whole milk and purchase a high quality milk replacer to feed the young calves. However, some milk replacers may vary in quality from other milk replacers and may have lower levels of vitamins and minerals than others. For example, some low quality milk replacers may lack a sufficient amount of vitamin E, which is important to promote immunoglobulin production in young calves. Moreover, milk replacers are unlikely to provide any protection to the calf against harmful microorganisms.
Liquid feed sources for preruminant calves known in the art such as hospital milk or low quality milk replacer suffer from the problem of being unable to supply to the preruminant calves' proper nutritional diet that is consistent and of high quality, and generally do not provide proper protection against harmful microorganisms. Other liquid feed sources such as colostrum and whole milk may not provide sufficient vitamins, minerals and immunoprotection, especially in stressful times within the preruminant calf's life. The present invention provides a solution to these problems, allowing the user to maintain health, maximize growth, and minimize mortality in preruminant calves.